Device for controlling the height and density of building blocks



July 17, 1962 G E. KANTA 3,044,137

DEVICE FOR CONTROLLING THE HEIGHT AND DENSITY OF BUILDING BLOCKS Filed Feb. 29, 1960 IN V EN TOR. 600190 E Keml'w BY QM, WW & M

ATTORNEYS 3,@44,137 Patented July 17, 1962 3,044 137 DEVICE FOR CONTROLIfING THE HEIGHT AND DENSITY OF BUILDING BLOCKS George E. Kanta, Three Forks, Gallatin County, Mont. Filed Feb. 29, 1960, Ser. No. 11,842 7 Claims. (Cl. 25-41) The invention relates to means for controlling the height and density of molded building blocks to closer limits than is possible under present practice.

The building blocks to which the invention pertains are formed of a mixture of hydraulic cement, aggregate and water. Such blocks are ordinarily made in automatic machines which employ the principle of vibration and pressure to form the blocks.

In machines of this type, a feed box is movable from a position beneath a hopper containing the semi-wet mixture to a position above the mold box into which the mixture is deposited from the feed box. The mold box is ordinarily vibrated to settle the material into the mold cavity, and a stripper head is lowered upon the vibrating mold box to further pack the material into the mold cavity and also size the block to correct height.

After the vibration of the mold box has stopped, the stripper head is raised, the mold being stripped off of the molded block, and the block, supported upon a pallet, is

removed to an off-bearing stand.

The height of the block is usually controlled by means of adjustable stops at each side of the mold box that limit the downward movement of the stripper head. However, this device does not control the height and density of the block to close enough limits, as the variation in aggregate, water content, gradation, etc. causes dilferent rates of settling of the mixture into the mold cavity.

Consequently, at times the mold cavity can contain too much material for the stripper head to size and at other times not enough material. To offset this situation, the feed box is ordinarily provided with a'cut-oft gate which may be raised and lowered manually to leave such an amount of material over the mold cavity as can be pressed to a predetermined height in a given time.

This type of feed control requires much time-taking supervision to maintain the density and height of the block uniform, and as a consequence, building blocks formed under present practice are frequently not of uniform height and density.

The present invention is designed to overcome the costly time delays required to manually adjust the cutoff gate of the feed box, and to automatically control the height and density of building blocks to closer limits than under present practice.

It is, therefore, a primary object of the invention to provide a device for automatically controlling the height and density of building blocks to very close limits.

Another object of the invention is the provision of such a device which checks the height of each block as it comes from the block machine, utilizing any differences in height thereof to automatically control the amount of material left over the feed box in the formation of the next succeeding block.

It is also an object of the invention to provide such a device in connection with a block machine, in which the amount of material left over the top of the mold cavity in the formation of each block is governed by the height of the next preceding finished block, whereby if the height of a finished block is too low or too high, more or less material, respectively, will be left over the top of the mold cavity in the formation of the next succeeding block.

Finally, it is an object of the invention to provide a device of the character referred to including an adjustable tail wheel at the rear end of the feed box and means governed by the height of each finished block for con trolling the raising or lowering of the tail wheel of the feed box, so as to leave thecorrect amount of material over the mold box for formation of the next succeeding block.

The above and other objects, apparent from the drawings and following description, may be attained, the above described difficulties overcome and the advantages and results obtained, by the apparatus, construction, arrangement and combinations, subcombinations and parts which comprise the present invention, a preferred embodiment of which, illustrative of the best mode in which applicant has contemplated applying the principle, being set forth in detail in the following description and illustrated in the accompanying drawings.

In general terms, the invention may be described as associated with a block machine including a feed box movable between a material-supply hopper and a mold box, and a stripper head movable vertically toward and from the mold box.

The movable feed box is supported upon front wheels, located at a point spaced from the forward end of the box, and a vertically adjustable tail wheel, located at the rear end thereof and adapted to be adjusted vertically by means of an electrically actuated linear actuator.

Each block is formed in the mold box upon a pallet of metal or wood, and when the mold box is stripped from the finished block, the block supported upon this pallet is removed to an off-bearing stand.

A pivotally mounted height transfer arm is provided at one end with a finger for contacting the top of the finished block uponthe off-bearing stand and has mercury tube switches at its other end for completing a circuit to the linear actuator in the event the finished block is too high or too low, whereby the linear actuator will automatically adjust the tail wheel of the feed box in order to leave the correct amount of material over the mold box for forming of the next succeeding block of desired height and density.

The contact finger of the height transfer arm may be moved into contact with the top of the finished block by gravity and normally held out of contact therewith by means of a solenoid, energized by a cam-operated switch upon the main shaft of the block machine.

Having thus briefly described the invention, reference is now made to the accompanying drawings, in which;

FIG. 1 is a diagrammatic view of a preferred embodiment of the invention; and

FIG. 2 is an enlarged detail section taken on the line 2-2, FIG. 1.

Referring now more particularly to the embodiment of the invention illustrated, in which similar numerals refer to similar parts throughout, a block machine is shown diagrammatically comprising the main shaft 5., mold box 2, material-supply hopper 3, feed box 4-, movable laterally between the hopper and the mold box, and stripper head 5, movable vertically toward and from the mold box.

The feed box 4 is provided with front wheels 6 located at a point spaced from the forward end of the box and movable upon the track rails 7; A tail wheel 8, movable upon the track trail 9, is located at the rear end of the feed box and mounted for vertical adjustment.

As shown in FIG. 1, the tail whee-l is mounted upon the horizontal arm 10 of abell crank lever, indicated generally at 11, fulcrumed at 12 upon the feed box. The vertical arm 13 of the bell crank lever is pivotally connected as at 14 to the longitudinal slidable rod 15 of an electrical linear actuator 15, mounted upon the rear portion of the feed box.

In the operation of the block machine, a pallet 17 of steel or wood, is placed beneath the mold box 2. The feed box 4 is moved to the rear, or to the right as viewed in FIG. 1, to a'position beneath the material-supply hopper 3, Where the box receives a charge of the semi-Wet mixture of cement and aggregate.

The feed box is then moved forwardiy, or to the left, to the position shown in FIG. 1, above the mold box 2 so as to deposit the charge of material in the cavity of the mold box. The mold box may be vibrated in conventional manner to settle the material into the mold cavity.

The feed box 4 is then withdrawn rearward-1y, or to the right, and the stripper head 5 is lowered into the still vibrating mold box to further pack the material into the mold cavity and to size the block to correct height.

When the vibration has ceased, the mold box is stripped off of the molded block and the block, as indicated at 18, resting upon the pallet 17, is carried forward to the offbearing stand 19, as shown in FIG. 1.

A height transfer arm 29 is pivoted at 21 upon a bracket 22 supported upon the off-bearing stand 19 and provided at one end with a finger 23, which may be adjustably mounted as by a locking nut 24.

As shown in FIG. 1, the finger 23 of the height transfer arm may be moved into contact with the top of the finished block 18 by gravity, and it is normally raised from the block "as by a solenoid 25 mounted in a frame 26 carried by the bracket 22, the movable armature 27 of the solenoid being pivotally connected to the height transfer arm as indicated at 28.

Instead of having the height transfer arm movable by gravity to contact the block, and movable away from the block by the solenoid, as shown in FIG. 1, it should be understood that the pivoted height transfer arm may be held away from the top of the block by gravity and be moved toward the block by a solenoid.

Wires 29 and 30 are connected to opposite ends of the winding on the solenoid 25, the Wire 29 being con nected to the line wire 31 and the wire 36 being connected to the line wire 32. A normally closed camoperated switch 33 is interposed in the Wire 30; whereby the solenoid 25 is normally energized so as to hold the transfer arm raised off of the block,

The switch 33 is adaptedto be opened for a short period, during each cycle of operation of the block machine, by means of a cam nub 34 on the cam 35 fixed upon the main shaft 1 of the block machine.

A pair of mercury tube switches 36 and 37 are mounted upon a lever 38, pivoted at 39 upon the bracket 22. One

end of the lever 38 is connected by a link 40 to the opposite end of the height transfer arm 20 from the contact finger 23.

Both of these mercury tube switches are connected by a common wire 41 to the line wire 31. The mercury switch 36 is connected by' a wire 42 with one end of the linear actuator'lti, and the mercury switch 37 is conactuator 16. V This switch is adapted to be operated by the cam nub 46 on the main shaft cam 35.

The cam nubs 34 and 46 are so spaced and located on the cam 35 that the switch 33 will be opened by the cam nub 34 before the switch 45 is closed by the cam nub 46, and will remain open until the switch 45 has again opened by the cam nub 46 moving out of contact therewith.

It should also be noted that the cam nubs 34 and 46 should be laterally oifsetlon the cam wheel 35, and that the switches 33 and 45 should be correspondingly offset, so that neither cam nub will operate the switch shown on the other side in FIG. 1.

As each finished block 18 is stripped from the mold box 2, the block is immediately removed from the block machine and placed upon the cit-beating stand 19. The

4 cam-operated switch 33 being normally closed, the solenoid 25 is normally energized, thus holding the contact finger 23 of the transfer arm .20 raised above the block.

As the cam 35 is rotated by the main shaft of the block machine, the cam. nub 34 thereon will contact the switch 33, opening the same and tie-energizing the solenoid 25 so that the height transfer arm 2i will be operated by gravity lowering the contact finger 23 thereof into contact with the top of the block 18. Immediately thereafter, the switch 45 is closed by the cam nub 46.

If the block 18 is too high, the too high mercury switch 35 will be closed, closing the circuit from the line wire 31, wire 41, mercury switch 36, wire 42, linear actuator 16, and wire 44 to the line wire 32.

The linear actuator will thus be actuated to lower th tail Wheel 8 of the feed box 4, so as to lower the forward or left end of the feed box to leave less material over the cavity of the mold box 2 in forming the next succeeding block in the machine.

After the cam nub 46 has moved out of contact with the switch 45, opening said switch, the cam nub 34 will then move out of contact with the switch 33, again closing said switch. 7

In the same manner, if the block 18 is too low, the too low mercury switch 37 will be closed, closing the circuit to the linear actuator through the wire 43, and actuating the linear actuator to raise the tail wheel and raise the forward end of the feed box to leave a greater amount of material over the cavity of the mold box.

If the height of the blocklS is within the required limits, neither of the mercury switches will be closed, and the adjustment of the tail wheel of the feed box will remain the same.

From the above it will be obvious that with the invention the height of each block is checked as it comes from the block machine,.and if the same is beyond the desired limits, the device will automatically actuate an electric linear actuator which will control the amount of material left over the top of the mold box in the molding of the next succeeding block in the machine.

Thus, the height and density of the blocks being formed upon the machine may be accurately controlled within very close limits, and the operation will be aut0- matic and will not require any manual adjustment of the feed box cut-oif gate.

It is well known that some concrete block machines are arranged so as to make two or more blocks on a pallet in each operation of the machine. In such cases, it would only be necessary for the controlling device to check the height of one block on each pallet because all blocks formed at the same time on one pallet would be of the same height.

In the foregoing description, certain terms have been used for brevity, clearness and understanding, but no unnecessary limitations are to be implied therefrom beyond the requirements of the-prior art, because such words are used for descriptive purposes herein and are intended to be broadly construed.

Moreover, the embodiments of the improved construction illustrated and described herein are by way of example, and the scope of the present invention is not limited to the exact details of construction. 7

Having now described the invention or discovery, the construction, the operation and use of preferred embodiments thereof, and the advantageous new and useful results obtained thereby; the new and useful construction, and reasonable mechanical equivalents thereof obvious to those skilled in the art, are set forth in the appended claims.

a device for controlling the height and density of blocks spasm? formed in the machine, said device comprising a support spaced from the mold box for supporting a block in upright position after it is removed from the mold box, a pivoted height transfer arm located adjacent to said sup port, means upon said arm for contacting a block positioned upon said support, a solenoid normally holding said arm out of contact with the block on said support, an electric circuit in which said solenoid is located, a normally closed switch in said circuit, cam means on the main shaft for momentarily opening said switch at a predetermined time and for deenergizing the solenoid and causing said arm to move into contact with the block, a bell crank for adjusting the feed box vertically relative to the mold box for controlling the amount of material left over the mold box for forming the next succeeding block in the machine, a linear actuator controlling said bell crank, a normally open electric circuit connected to the linear actuator, two normally open mercury switches in said normally open circuit, means operatively connecting said height transfer arm to said mercury switches for tilting one of said mercury switches to closed position when the block on said support is too high and for tilting the other mercury switch to closed position when said block is too low for actuating said linear actuator to operate said bell crank to vertically adjust the feed box inversely to the height of said block, a normally open switch in said normally open circuit, and a cam on the main shaft for closing said normally open switch at a predetermined time after said height transfer arm has contacted said block.

2. In a block machine as defined in claim 1, a device for controlling the height and density of blocks formed in the machine, in which the feed box is provided with wheels intermediate its ends, and a tail wheel is journalled on the bell crank for vertically adjusting the forward end of the feed box.

3. In a block machine including a mold box, a material supply hopper, a feed box movable between the hopper and the mold box, a stripper head movable vertically toward and from the mold box, and a main shaft,

a device for controlling the height and density of blocks formed in the' machine, said device comprising a support spaced from the mold box for supporting a block in upright position after it is removed from the mold box, a pivoted height transfer arm located adjacent to said support, means upon said arm for contacting the top of a block positioned upon said support, means including a solenoid for normally holding said arm out of contact with the block on said support, an electric circuit connected to said solenoid, a switch in said circuit, means actuated by the main shaft for operating said switch for actuating the solenoid for causing the arm to move into contact with the block, means for adjusting the feed box vertically relative to the mold box for controlling the amount of material left over the mold box for forming the next succeeding block in the machine, a linear actuator controlling said vertical adjusting means, a normally open electric circuit for the linear-actuator, means operated by the main shaft for closing said normally open circuit at a predetermined time after said height transfer arm has contacted the block, two spaced normally open switches in said normally open circuit, means upon said arm for closing one of said last named switches when the block upon said support is too high and for-closing the other switch when said block is too low for actuating said linear actuator to vertically adjust the feed box inversely to the height of the block on said support.

4. In a block machine including a mold box, a material supply hopper, a feed box movable between the hopper and the mold box, a stripper head movable vertically toward and from the mold box, and a main shaft, 2. device for controlling the height and density of blocks formed in the machine, said device comprising a support spaced from the mold box for supporting a block in upright position after it is removed from the mold box, a

pivoted height transfer arm located adjacent to said sup port, means upon said arm for contacting the top of a the next succeeding block in the machine, a linear actuator controlling said vertical adjusting means, a normally open electric circuit for the linear actuator, means operated by the main shaft for closing said normally open circuit at a predetermined time after said height transfer arm has contacted the block, two normally open tilting mercury switches in saidcircuit, means upon said arm for tilting one of said mercury switches to closed position when the block upon said support is too high and for tilting the other mercury switch to closed position when the said block is too low for actuating said linear actuator to vertically adjust the feed box inversely to the height of the block on said support.

5. In a block machine including a mold box, a material supply hopper, a feed box movable between the hopper and the mold box, a stripper head movable vertically toward and from the mold box, and a main shaft, a device for controlling the height and density of blocks formed in the machine, said device comprising a support spaced from the mold box for supporting a block in upright position after it is removed from the mold box, a pivoted height transfer arm located adjacent to said support, means upon said arm for contacting the top of a block positioned upon said support, means including a solenoid for normally holding said arm out of contact with the block on said support, an electric circuit connected to said solenoid, a switch in said circuit, means actuated by the main shaft for operating said switch for actuating said solenoid for causing the arm to move into contact with the block, means for adjusting the feed box vertically relative to the mold box for controlling the amount of material left over the mold box for forming the next succeeding block in the machine, a linear actuator controlling said vertical adjusting means, a normally open electric circuit for the linear actuator, two spaced normally open switches in said circuit, means upon said arm for closing one of said normally open switches when the block upon said support is too high and for closing the other normally open switch when said block is too low for actuating said linear actuator to vertically adjust the feed box inversely to the height of the block on said support, a normally open switch in said normally open circuit, and means operated by the main shaft for closing said normally open switch at a predetermined time after said height transfer arm has contacted said block.

6. In a block machine including a mold box, a material supply hopper, a feed box movable between the hopper and the mold box, a stripper head movable vertically toward and from the mold'box, and a main shaft, a device for controlling the height and density of blocks formed in the machine, said device comprising a support spaced from the mold box for supporting a block in upright position after it is removed from the mold box, a pivoted height transfer arm located adjacent to said support, means upon said arm for contacting the top of a block positioned upon said support, means including a solenoid for normally holding said arm out of contact with the block on saidsupport, an electric circuit connected to said solenoid, a switch in said circuit, means actuated by the main shaft for operating said switch for actuating said solenoid for causing the arm to move into contact with the block, means for adjusting the feed box vertically relative to the mold box for controlling the amount of material left over the moldbox for forming the next succeeding block in the machine, a linear actuator controlling said vertical adjusting means, a normally open electric circuit for the linear actuator, two normally opentilting mercury switches in said circuit, means upon said arm for tilting one of said mercury switches to closed position when the block upon said support is too high and for tilting the other mercury switch to closed position when the said block is too low for actuating said linear actuator to vertically adjust the feed *box inversely to the height of the block on said support, a normally open switch in said normally open circuit, and means operated by the main shaft for closingsaid normally open switch at a predetermined time after said height transfer arm has contacted said 'block.

7. In a block machine including a mold box, a material supply hopper, a feed box movable between the hopper and the mold box, a stripper head movable verticallytoward and from the mold box, and a main shaft, a device for controlling the height and density of blocks formed in the machine, said device comprising a support 20 spaced from the mold :box for supporting a block in upright position after it is removed from the mold box, a pivoted height transfer arm located adjacent to said support, means upon said arm for contacting the top of a block positioned upon said support, means including a 25 solenoid for normally holding said arm out of contact with the block on said support, an electric circuit con nected to said solenoid, a switch insaid circuit, means actuated by the main shafit for operating said switch for actuating said solenoid or causing the arm to move into contact with the block, means for adjusting the feed box vertical-1y relative to the mold box for controlling the amount of material left over the mold box for forming the next succeeding block in the machine, a linear actuator controlling said vertical adjusting means, a normally open electric circuit for the linear actuator, and switch means in said normally open circuit actuated by movement of said arm for actuating said linear actuator to vertically adjust the feed box inversely to the height of the blockon said support, a normally open switch in said normally open circuit, and means operated by the main shaft for closing said normally open switch at a predetermined time after said height transfer arm has contacted said lalock.

References Cited in the file of this patent UNITED STATES PATENTS 2,357,860 Whitaker Sept. 12, 1944 2,664,557 Sargrove u Dec. 29, 1953 2,672,669 Davis Mar. 23, 1954 2,686,950 Zevely Aug. 24, 1954 2,884,531 Bosch Apr. 28, 1959 2,957,221 Zmania eta'l. Oct. 25, 1960 2,957,222 Zmania et al. Oct. 25, 1960 

